Auto-Rx can be stored indefintely, if in cold temperatures, run it under hot water for 10 minutes before using. Keep bottle cap on tight, (shake it up if it's been stored for a time) after using hotwater above if in frigid climates. Your good to go. Have noticed several posts where Auto-Rx customers running third application which is fine (after second application when you still see "crud' wipe it with a rag and believe you will see it come right off of metal) you can just fill with oil and run a couple hundred miles and oil will do same as rag outlined above. Just a tip. New Subject -New Engines & Auto-Rx, we just did third application to a Ford Product with less than 1000 miles. Ran Auto-rx this time 750 miles, filter very dirty (not sludge or oil just dirt) and enough metal particulates to fill half of a filter. Same results as other two Ford Products except 750 miles instead of 500 miles, 750 miles
very noticable results, fast.